As a counterpoint: is your JS webapp really going to live, in its current form, for 5 years? Experience has taught me that there have been enough shifts - to mobile, especially - that betting in the long term like this might not be worth it. If you've structured your app well, the front-end JS is separated from the backend APIs, etc. etc. - a rewrite of that is not a rewrite of the entire app. So if React speeds your site up by a factor of whatever, go for it.
In any case, even if it is, surely an older framework is fine? I see Backbone in the "slow or stagnated innovation" part of the chart - it isn't broken. It works fine. Seems confusing to simultaneously complain about the web framework "industry" moving too fast, and individual frameworks moving too slow.
In any case, even if it is, surely an older framework is fine? I see Backbone in the "slow or stagnated innovation" part of the chart - it isn't broken. It works fine. Seems confusing to simultaneously complain about the web framework "industry" moving too fast, and individual frameworks moving too slow.